1 | /* $NetBSD: zlib.h,v 1.14 2009/03/25 01:26:12 darran Exp $ */ |
2 | |
3 | /* zlib.h -- interface of the 'zlib' general purpose compression library |
4 | version 1.1.4, March 11th, 2002 |
5 | |
6 | Copyright (C) 1995-2002 Jean-loup Gailly and Mark Adler |
7 | |
8 | This software is provided 'as-is', without any express or implied |
9 | warranty. In no event will the authors be held liable for any damages |
10 | arising from the use of this software. |
11 | |
12 | Permission is granted to anyone to use this software for any purpose, |
13 | including commercial applications, and to alter it and redistribute it |
14 | freely, subject to the following restrictions: |
15 | |
16 | 1. The origin of this software must not be misrepresented; you must not |
17 | claim that you wrote the original software. If you use this software |
18 | in a product, an acknowledgment in the product documentation would be |
19 | appreciated but is not required. |
20 | 2. Altered source versions must be plainly marked as such, and must not be |
21 | misrepresented as being the original software. |
22 | 3. This notice may not be removed or altered from any source distribution. |
23 | |
24 | Jean-loup Gailly Mark Adler |
25 | jloup@gzip.org madler@alumni.caltech.edu |
26 | |
27 | |
28 | The data format used by the zlib library is described by RFCs (Request for |
29 | Comments) 1950 to 1952 in the files ftp://ds.internic.net/rfc/rfc1950.txt |
30 | (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format). |
31 | */ |
32 | |
33 | #ifndef _NET_ZLIB_H_ |
34 | #define _NET_ZLIB_H_ |
35 | |
36 | #ifdef __NetBSD__ |
37 | #include <sys/cdefs.h> |
38 | #endif |
39 | |
40 | /* +++ zconf.h */ |
41 | /* zconf.h -- configuration of the zlib compression library |
42 | * Copyright (C) 1995-2002 Jean-loup Gailly. |
43 | * For conditions of distribution and use, see copyright notice in zlib.h |
44 | */ |
45 | |
46 | /* @(#) $Id: zlib.h,v 1.14 2009/03/25 01:26:12 darran Exp $ */ |
47 | |
48 | #ifndef ZCONF_H |
49 | #define ZCONF_H |
50 | |
51 | /* |
52 | * Warning: This file pollutes the user's namespace with: |
53 | * Byte Bytef EXPORT FAR OF STDC |
54 | * charf intf uInt uIntf uLong uLonf |
55 | * Programs using this library appear to expect those... |
56 | */ |
57 | |
58 | #include <sys/types.h> |
59 | |
60 | /* |
61 | * If you *really* need a unique prefix for all types and library functions, |
62 | * compile with -DZ_PREFIX. The "standard" zlib should be compiled without it. |
63 | */ |
64 | #ifdef Z_PREFIX |
65 | # define deflateInit_ z_deflateInit_ |
66 | # define deflate z_deflate |
67 | # define deflateEnd z_deflateEnd |
68 | # define inflateInit_ z_inflateInit_ |
69 | # define inflate z_inflate |
70 | # define inflateEnd z_inflateEnd |
71 | # define deflateInit2_ z_deflateInit2_ |
72 | # define deflateSetDictionary z_deflateSetDictionary |
73 | # define deflateCopy z_deflateCopy |
74 | # define deflateReset z_deflateReset |
75 | # define deflateParams z_deflateParams |
76 | # define inflateInit2_ z_inflateInit2_ |
77 | # define inflateSetDictionary z_inflateSetDictionary |
78 | # define inflateSync z_inflateSync |
79 | # define inflateSyncPoint z_inflateSyncPoint |
80 | # define inflateReset z_inflateReset |
81 | # define compress z_compress |
82 | # define compress2 z_compress2 |
83 | # define uncompress z_uncompress |
84 | # define adler32 z_adler32 |
85 | # define crc32 z_crc32 |
86 | # define get_crc_table z_get_crc_table |
87 | |
88 | # define Byte z_Byte |
89 | # define uInt z_uInt |
90 | # define uLong z_uLong |
91 | # define Bytef z_Bytef |
92 | # define charf z_charf |
93 | # define intf z_intf |
94 | # define uIntf z_uIntf |
95 | # define uLongf z_uLongf |
96 | # define voidpf z_voidpf |
97 | # define voidp z_voidp |
98 | #endif |
99 | |
100 | #ifndef __32BIT__ |
101 | /* Don't be alarmed; this just means we have at least 32-bits */ |
102 | # define __32BIT__ |
103 | #endif |
104 | |
105 | /* |
106 | * Compile with -DMAXSEG_64K if the alloc function cannot allocate more |
107 | * than 64k bytes at a time (needed on systems with 16-bit int). |
108 | */ |
109 | #if defined(MSDOS) && !defined(__32BIT__) |
110 | # define MAXSEG_64K |
111 | #endif |
112 | |
113 | #if 0 |
114 | /* XXX: Are there machines where we should define this? m68k? */ |
115 | # define UNALIGNED_OK |
116 | #endif |
117 | |
118 | #if (defined(__STDC__) || defined(__cplusplus)) && !defined(STDC) |
119 | /* XXX: Look out - this is used in zutil.h and elsewhere... */ |
120 | # define STDC |
121 | #endif |
122 | #if defined(__STDC__) || defined(__cplusplus) || defined(__OS2__) |
123 | # ifndef STDC |
124 | # define STDC |
125 | # endif |
126 | #endif |
127 | |
128 | #ifndef STDC |
129 | # ifndef const |
130 | # define const |
131 | # endif |
132 | #endif |
133 | |
134 | /* Some Mac compilers merge all .h files incorrectly: */ |
135 | #if defined(__MWERKS__) || defined(applec) ||defined(THINK_C) ||defined(__SC__) |
136 | # define NO_DUMMY_DECL |
137 | #endif |
138 | |
139 | /* Old Borland C incorrectly complains about missing returns: */ |
140 | #if defined(__BORLANDC__) && (__BORLANDC__ < 0x500) |
141 | # define NEED_DUMMY_RETURN |
142 | #endif |
143 | |
144 | |
145 | /* Maximum value for memLevel in deflateInit2 */ |
146 | #ifndef MAX_MEM_LEVEL |
147 | # ifdef MAXSEG_64K |
148 | # define MAX_MEM_LEVEL 8 |
149 | # else |
150 | # define MAX_MEM_LEVEL 9 |
151 | # endif |
152 | #endif |
153 | |
154 | /* Maximum value for windowBits in deflateInit2 and inflateInit2. |
155 | * WARNING: reducing MAX_WBITS makes minigzip unable to extract .gz files |
156 | * created by gzip. (Files created by minigzip can still be extracted by |
157 | * gzip.) |
158 | */ |
159 | #ifndef MAX_WBITS |
160 | # define MAX_WBITS 15 /* 32K LZ77 window */ |
161 | #endif |
162 | |
163 | /* The memory requirements for deflate are (in bytes): |
164 | (1 << (windowBits+2)) + (1 << (memLevel+9)) |
165 | that is: 128K for windowBits=15 + 128K for memLevel = 8 (default values) |
166 | plus a few kilobytes for small objects. For example, if you want to reduce |
167 | the default memory requirements from 256K to 128K, compile with |
168 | make CFLAGS="-O -DMAX_WBITS=14 -DMAX_MEM_LEVEL=7" |
169 | Of course this will generally degrade compression (there's no free lunch). |
170 | |
171 | The memory requirements for inflate are (in bytes) 1 << windowBits |
172 | that is, 32K for windowBits=15 (default value) plus a few kilobytes |
173 | for small objects. |
174 | */ |
175 | |
176 | /* Type declarations */ |
177 | |
178 | #ifndef __P /* function prototypes */ |
179 | # ifdef STDC |
180 | # define __P(args) args |
181 | # else |
182 | # define __P(args) () |
183 | # endif |
184 | #endif |
185 | |
186 | /* The following definitions for FAR are needed only for MSDOS mixed |
187 | * model programming (small or medium model with some far allocations). |
188 | * This was tested only with MSC; for other MSDOS compilers you may have |
189 | * to define NO_MEMCPY in zutil.h. If you don't need the mixed model, |
190 | * just define FAR to be empty. |
191 | */ |
192 | #if (defined(M_I86SM) || defined(M_I86MM)) && !defined(__32BIT__) |
193 | /* MSC small or medium model */ |
194 | # define SMALL_MEDIUM |
195 | # ifdef _MSC_VER |
196 | # define FAR _far |
197 | # else |
198 | # define FAR far |
199 | # endif |
200 | #endif |
201 | #if defined(__BORLANDC__) && (defined(__SMALL__) || defined(__MEDIUM__)) |
202 | # ifndef __32BIT__ |
203 | # define SMALL_MEDIUM |
204 | # define FAR _far |
205 | # endif |
206 | #endif |
207 | |
208 | /* Compile with -DZLIB_DLL for Windows DLL support */ |
209 | #if defined(ZLIB_DLL) |
210 | # if defined(_WINDOWS) || defined(WINDOWS) |
211 | # ifdef FAR |
212 | # undef FAR |
213 | # endif |
214 | # include <windows.h> |
215 | # define ZEXPORT WINAPI |
216 | # ifdef WIN32 |
217 | # define ZEXPORTVA WINAPIV |
218 | # else |
219 | # define ZEXPORTVA FAR _cdecl _export |
220 | # endif |
221 | # endif |
222 | # if defined (__BORLANDC__) |
223 | # if (__BORLANDC__ >= 0x0500) && defined (WIN32) |
224 | # include <windows.h> |
225 | # define ZEXPORT __declspec(dllexport) WINAPI |
226 | # define ZEXPORTRVA __declspec(dllexport) WINAPIV |
227 | # else |
228 | # if defined (_Windows) && defined (__DLL__) |
229 | # define ZEXPORT _export |
230 | # define ZEXPORTVA _export |
231 | # endif |
232 | # endif |
233 | # endif |
234 | #endif |
235 | |
236 | #if defined (__BEOS__) |
237 | # if defined (ZLIB_DLL) |
238 | # define ZEXTERN extern __declspec(dllexport) |
239 | # else |
240 | # define ZEXTERN extern __declspec(dllimport) |
241 | # endif |
242 | #endif |
243 | |
244 | #ifndef ZEXPORT |
245 | # define ZEXPORT |
246 | #endif |
247 | #ifndef ZEXPORTVA |
248 | # define ZEXPORTVA |
249 | #endif |
250 | #ifndef ZEXTERN |
251 | # define ZEXTERN extern |
252 | #endif |
253 | |
254 | #ifndef FAR |
255 | # define FAR |
256 | #endif |
257 | |
258 | #if !defined(MACOS) && !defined(TARGET_OS_MAC) |
259 | typedef unsigned char Byte; /* 8 bits */ |
260 | #endif |
261 | typedef unsigned int uInt; /* 16 bits or more */ |
262 | typedef unsigned long uLong; /* 32 bits or more */ |
263 | |
264 | #ifdef SMALL_MEDIUM |
265 | /* Borland C/C++ and some old MSC versions ignore FAR inside typedef */ |
266 | # define Bytef Byte FAR |
267 | #else |
268 | typedef Byte FAR Bytef; |
269 | #endif |
270 | typedef char FAR charf; |
271 | typedef int FAR intf; |
272 | typedef uInt FAR uIntf; |
273 | typedef uLong FAR uLongf; |
274 | |
275 | #ifdef STDC |
276 | typedef void FAR *voidpf; |
277 | typedef void *voidp; |
278 | #else |
279 | typedef Byte FAR *voidpf; |
280 | typedef Byte *voidp; |
281 | #endif |
282 | |
283 | #if (defined(HAVE_UNISTD_H) || defined(__NetBSD__)) && !defined(_KERNEL) |
284 | # include <sys/types.h> /* for off_t */ |
285 | # include <unistd.h> /* for SEEK_* and off_t */ |
286 | # define z_off_t off_t |
287 | #endif |
288 | #ifndef SEEK_SET |
289 | # define SEEK_SET 0 /* Seek from beginning of file. */ |
290 | # define SEEK_CUR 1 /* Seek from current position. */ |
291 | # define SEEK_END 2 /* Set file pointer to EOF plus "offset" */ |
292 | #endif |
293 | #ifndef z_off_t |
294 | # define z_off_t long |
295 | #endif |
296 | |
297 | /* MVS linker does not support external names larger than 8 bytes */ |
298 | #if defined(__MVS__) |
299 | # pragma map(deflateInit_,"DEIN") |
300 | # pragma map(deflateInit2_,"DEIN2") |
301 | # pragma map(deflateEnd,"DEEND") |
302 | # pragma map(inflateInit_,"ININ") |
303 | # pragma map(inflateInit2_,"ININ2") |
304 | # pragma map(inflateEnd,"INEND") |
305 | # pragma map(inflateSync,"INSY") |
306 | # pragma map(inflateSetDictionary,"INSEDI") |
307 | # pragma map(inflate_blocks,"INBL") |
308 | # pragma map(inflate_blocks_new,"INBLNE") |
309 | # pragma map(inflate_blocks_free,"INBLFR") |
310 | # pragma map(inflate_blocks_reset,"INBLRE") |
311 | # pragma map(inflate_codes_free,"INCOFR") |
312 | # pragma map(inflate_codes,"INCO") |
313 | # pragma map(inflate_fast,"INFA") |
314 | # pragma map(inflate_flush,"INFLU") |
315 | # pragma map(inflate_mask,"INMA") |
316 | # pragma map(inflate_set_dictionary,"INSEDI2") |
317 | # pragma map(inflate_copyright,"INCOPY") |
318 | # pragma map(inflate_trees_bits,"INTRBI") |
319 | # pragma map(inflate_trees_dynamic,"INTRDY") |
320 | # pragma map(inflate_trees_fixed,"INTRFI") |
321 | # pragma map(inflate_trees_free,"INTRFR") |
322 | #endif |
323 | |
324 | #endif /* !ZCONF_H */ |
325 | /* --- zconf.h */ |
326 | |
327 | #ifndef ZLIB_H |
328 | #define ZLIB_H |
329 | #ifdef __cplusplus |
330 | extern "C" { |
331 | #endif |
332 | |
333 | #define ZLIB_VERSION "1.1.4" |
334 | |
335 | /* |
336 | The 'zlib' compression library provides in-memory compression and |
337 | decompression functions, including integrity checks of the uncompressed |
338 | data. This version of the library supports only one compression method |
339 | (deflation) but other algorithms will be added later and will have the same |
340 | stream interface. |
341 | |
342 | Compression can be done in a single step if the buffers are large |
343 | enough (for example if an input file is mmap'ed), or can be done by |
344 | repeated calls of the compression function. In the latter case, the |
345 | application must provide more input and/or consume the output |
346 | (providing more output space) before each call. |
347 | |
348 | The library also supports reading and writing files in gzip (.gz) format |
349 | with an interface similar to that of stdio. |
350 | |
351 | The library does not install any signal handler. The decoder checks |
352 | the consistency of the compressed data, so the library should never |
353 | crash even in case of corrupted input. |
354 | */ |
355 | |
356 | typedef voidpf (*alloc_func)(voidpf, uInt, uInt); |
357 | typedef void (*free_func)(voidpf, voidpf); |
358 | |
359 | struct internal_state; |
360 | |
361 | typedef struct z_stream_s { |
362 | Bytef *next_in; /* next input byte */ |
363 | uInt avail_in; /* number of bytes available at next_in */ |
364 | uLong total_in; /* total nb of input bytes read so far */ |
365 | |
366 | Bytef *next_out; /* next output byte should be put there */ |
367 | uInt avail_out; /* remaining free space at next_out */ |
368 | uLong total_out; /* total nb of bytes output so far */ |
369 | |
370 | const char *msg; /* last error message, NULL if no error */ |
371 | struct internal_state FAR *state; /* not visible by applications */ |
372 | |
373 | alloc_func zalloc; /* used to allocate the internal state */ |
374 | free_func zfree; /* used to free the internal state */ |
375 | voidpf opaque; /* private data object passed to zalloc and zfree */ |
376 | |
377 | int data_type; /* best guess about the data type: ascii or binary */ |
378 | uLong adler; /* adler32 value of the uncompressed data */ |
379 | uLong reserved; /* reserved for future use */ |
380 | } z_stream; |
381 | |
382 | typedef z_stream FAR *z_streamp; |
383 | |
384 | /* |
385 | The application must update next_in and avail_in when avail_in has |
386 | dropped to zero. It must update next_out and avail_out when avail_out |
387 | has dropped to zero. The application must initialize zalloc, zfree and |
388 | opaque before calling the init function. All other fields are set by the |
389 | compression library and must not be updated by the application. |
390 | |
391 | The opaque value provided by the application will be passed as the first |
392 | parameter for calls of zalloc and zfree. This can be useful for custom |
393 | memory management. The compression library attaches no meaning to the |
394 | opaque value. |
395 | |
396 | zalloc must return Z_NULL if there is not enough memory for the object. |
397 | If zlib is used in a multi-threaded application, zalloc and zfree must be |
398 | thread safe. |
399 | |
400 | On 16-bit systems, the functions zalloc and zfree must be able to allocate |
401 | exactly 65536 bytes, but will not be required to allocate more than this |
402 | if the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS, |
403 | pointers returned by zalloc for objects of exactly 65536 bytes *must* |
404 | have their offset normalized to zero. The default allocation function |
405 | provided by this library ensures this (see zutil.c). To reduce memory |
406 | requirements and avoid any allocation of 64K objects, at the expense of |
407 | compression ratio, compile the library with -DMAX_WBITS=14 (see zconf.h). |
408 | |
409 | The fields total_in and total_out can be used for statistics or |
410 | progress reports. After compression, total_in holds the total size of |
411 | the uncompressed data and may be saved for use in the decompressor |
412 | (particularly if the decompressor wants to decompress everything in |
413 | a single step). |
414 | */ |
415 | |
416 | /* constants */ |
417 | |
418 | #define Z_NO_FLUSH 0 |
419 | #define Z_PARTIAL_FLUSH 1 /* will be removed, use Z_SYNC_FLUSH instead */ |
420 | #define Z_PACKET_FLUSH 2 |
421 | #define Z_SYNC_FLUSH 3 |
422 | #define Z_FULL_FLUSH 4 |
423 | #define Z_FINISH 5 |
424 | /* Allowed flush values; see deflate() below for details */ |
425 | |
426 | #define Z_OK 0 |
427 | #define Z_STREAM_END 1 |
428 | #define Z_NEED_DICT 2 |
429 | #define Z_ERRNO (-1) |
430 | #define Z_STREAM_ERROR (-2) |
431 | #define Z_DATA_ERROR (-3) |
432 | #define Z_MEM_ERROR (-4) |
433 | #define Z_BUF_ERROR (-5) |
434 | #define Z_VERSION_ERROR (-6) |
435 | /* Return codes for the compression/decompression functions. Negative |
436 | * values are errors, positive values are used for special but normal events. |
437 | */ |
438 | |
439 | #define Z_NO_COMPRESSION 0 |
440 | #define Z_BEST_SPEED 1 |
441 | #define Z_BEST_COMPRESSION 9 |
442 | #define Z_DEFAULT_COMPRESSION (-1) |
443 | /* compression levels */ |
444 | |
445 | #define Z_FILTERED 1 |
446 | #define Z_HUFFMAN_ONLY 2 |
447 | #define Z_DEFAULT_STRATEGY 0 |
448 | /* compression strategy; see deflateInit2() below for details */ |
449 | |
450 | #define Z_BINARY 0 |
451 | #define Z_ASCII 1 |
452 | #define Z_UNKNOWN 2 |
453 | /* Possible values of the data_type field */ |
454 | |
455 | #define Z_DEFLATED 8 |
456 | /* The deflate compression method (the only one supported in this version) */ |
457 | |
458 | #define Z_NULL 0 /* for initializing zalloc, zfree, opaque */ |
459 | |
460 | #define zlib_version zlibVersion() |
461 | /* for compatibility with versions < 1.0.2 */ |
462 | |
463 | /* basic functions */ |
464 | |
465 | ZEXTERN const char * ZEXPORT zlibVersion(void); |
466 | /* The application can compare zlibVersion and ZLIB_VERSION for consistency. |
467 | If the first character differs, the library code actually used is |
468 | not compatible with the zlib.h header file used by the application. |
469 | This check is automatically made by deflateInit and inflateInit. |
470 | */ |
471 | |
472 | /* |
473 | ZEXTERN int ZEXPORT deflateInit(z_streamp, int); |
474 | |
475 | Initializes the internal stream state for compression. The fields |
476 | zalloc, zfree and opaque must be initialized before by the caller. |
477 | If zalloc and zfree are set to Z_NULL, deflateInit updates them to |
478 | use default allocation functions. |
479 | |
480 | The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9: |
481 | 1 gives best speed, 9 gives best compression, 0 gives no compression at |
482 | all (the input data is simply copied a block at a time). |
483 | Z_DEFAULT_COMPRESSION requests a default compromise between speed and |
484 | compression (currently equivalent to level 6). |
485 | |
486 | deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not |
487 | enough memory, Z_STREAM_ERROR if level is not a valid compression level, |
488 | Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible |
489 | with the version assumed by the caller (ZLIB_VERSION). |
490 | msg is set to null if there is no error message. deflateInit does not |
491 | perform any compression: this will be done by deflate(). |
492 | */ |
493 | |
494 | |
495 | ZEXTERN int ZEXPORT deflate(z_streamp, int); |
496 | /* |
497 | deflate compresses as much data as possible, and stops when the input |
498 | buffer becomes empty or the output buffer becomes full. It may introduce some |
499 | output latency (reading input without producing any output) except when |
500 | forced to flush. |
501 | |
502 | The detailed semantics are as follows. deflate performs one or both of the |
503 | following actions: |
504 | |
505 | - Compress more input starting at next_in and update next_in and avail_in |
506 | accordingly. If not all input can be processed (because there is not |
507 | enough room in the output buffer), next_in and avail_in are updated and |
508 | processing will resume at this point for the next call of deflate(). |
509 | |
510 | - Provide more output starting at next_out and update next_out and avail_out |
511 | accordingly. This action is forced if the parameter flush is non zero. |
512 | Forcing flush frequently degrades the compression ratio, so this parameter |
513 | should be set only when necessary (in interactive applications). |
514 | Some output may be provided even if flush is not set. |
515 | |
516 | Before the call of deflate(), the application should ensure that at least |
517 | one of the actions is possible, by providing more input and/or consuming |
518 | more output, and updating avail_in or avail_out accordingly; avail_out |
519 | should never be zero before the call. The application can consume the |
520 | compressed output when it wants, for example when the output buffer is full |
521 | (avail_out == 0), or after each call of deflate(). If deflate returns Z_OK |
522 | and with zero avail_out, it must be called again after making room in the |
523 | output buffer because there might be more output pending. |
524 | |
525 | If the parameter flush is set to Z_SYNC_FLUSH, all pending output is |
526 | flushed to the output buffer and the output is aligned on a byte boundary, so |
527 | that the decompressor can get all input data available so far. (In particular |
528 | avail_in is zero after the call if enough output space has been provided |
529 | before the call.) Flushing may degrade compression for some compression |
530 | algorithms and so it should be used only when necessary. |
531 | |
532 | If flush is set to Z_FULL_FLUSH, all output is flushed as with |
533 | Z_SYNC_FLUSH, and the compression state is reset so that decompression can |
534 | restart from this point if previous compressed data has been damaged or if |
535 | random access is desired. Using Z_FULL_FLUSH too often can seriously degrade |
536 | the compression. |
537 | |
538 | If deflate returns with avail_out == 0, this function must be called again |
539 | with the same value of the flush parameter and more output space (updated |
540 | avail_out), until the flush is complete (deflate returns with non-zero |
541 | avail_out). |
542 | |
543 | If the parameter flush is set to Z_PACKET_FLUSH, the compression |
544 | block is terminated, and a zero-length stored block is output, |
545 | omitting the length bytes (the effect of this is that the 3-bit type |
546 | code 000 for a stored block is output, and the output is then |
547 | byte-aligned). This is designed for use at the end of a PPP packet. |
548 | |
549 | |
550 | If the parameter flush is set to Z_FINISH, pending input is processed, |
551 | pending output is flushed and deflate returns with Z_STREAM_END if there |
552 | was enough output space; if deflate returns with Z_OK, this function must be |
553 | called again with Z_FINISH and more output space (updated avail_out) but no |
554 | more input data, until it returns with Z_STREAM_END or an error. After |
555 | deflate has returned Z_STREAM_END, the only possible operations on the |
556 | stream are deflateReset or deflateEnd. |
557 | |
558 | Z_FINISH can be used immediately after deflateInit if all the compression |
559 | is to be done in a single step. In this case, avail_out must be at least |
560 | 0.1% larger than avail_in plus 12 bytes. If deflate does not return |
561 | Z_STREAM_END, then it must be called again as described above. |
562 | |
563 | deflate() sets strm->adler to the adler32 checksum of all input read |
564 | so far (that is, total_in bytes). |
565 | |
566 | deflate() may update data_type if it can make a good guess about |
567 | the input data type (Z_ASCII or Z_BINARY). In doubt, the data is considered |
568 | binary. This field is only for information purposes and does not affect |
569 | the compression algorithm in any manner. |
570 | |
571 | deflate() returns Z_OK if some progress has been made (more input |
572 | processed or more output produced), Z_STREAM_END if all input has been |
573 | consumed and all output has been produced (only when flush is set to |
574 | Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example |
575 | if next_in or next_out was NULL), Z_BUF_ERROR if no progress is possible |
576 | (for example avail_in or avail_out was zero). |
577 | */ |
578 | |
579 | |
580 | ZEXTERN int ZEXPORT deflateEnd(z_streamp); |
581 | /* |
582 | All dynamically allocated data structures for this stream are freed. |
583 | This function discards any unprocessed input and does not flush any |
584 | pending output. |
585 | |
586 | deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the |
587 | stream state was inconsistent, Z_DATA_ERROR if the stream was freed |
588 | prematurely (some input or output was discarded). In the error case, |
589 | msg may be set but then points to a static string (which must not be |
590 | deallocated). |
591 | */ |
592 | |
593 | |
594 | /* |
595 | ZEXTERN int ZEXPORT inflateInit(z_streamp); |
596 | |
597 | Initializes the internal stream state for decompression. The fields |
598 | next_in, avail_in, zalloc, zfree and opaque must be initialized before by |
599 | the caller. If next_in is not Z_NULL and avail_in is large enough (the exact |
600 | value depends on the compression method), inflateInit determines the |
601 | compression method from the zlib header and allocates all data structures |
602 | accordingly; otherwise the allocation will be deferred to the first call of |
603 | inflate. If zalloc and zfree are set to Z_NULL, inflateInit updates them to |
604 | use default allocation functions. |
605 | |
606 | inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough |
607 | memory, Z_VERSION_ERROR if the zlib library version is incompatible with the |
608 | version assumed by the caller. msg is set to null if there is no error |
609 | message. inflateInit does not perform any decompression apart from reading |
610 | the zlib header if present: this will be done by inflate(). (So next_in and |
611 | avail_in may be modified, but next_out and avail_out are unchanged.) |
612 | */ |
613 | |
614 | |
615 | ZEXTERN int ZEXPORT inflate(z_streamp, int); |
616 | /* |
617 | inflate decompresses as much data as possible, and stops when the input |
618 | buffer becomes empty or the output buffer becomes full. It may some |
619 | introduce some output latency (reading input without producing any output) |
620 | except when forced to flush. |
621 | |
622 | The detailed semantics are as follows. inflate performs one or both of the |
623 | following actions: |
624 | |
625 | - Decompress more input starting at next_in and update next_in and avail_in |
626 | accordingly. If not all input can be processed (because there is not |
627 | enough room in the output buffer), next_in is updated and processing |
628 | will resume at this point for the next call of inflate(). |
629 | |
630 | - Provide more output starting at next_out and update next_out and avail_out |
631 | accordingly. inflate() provides as much output as possible, until there |
632 | is no more input data or no more space in the output buffer (see below |
633 | about the flush parameter). |
634 | |
635 | Before the call of inflate(), the application should ensure that at least |
636 | one of the actions is possible, by providing more input and/or consuming |
637 | more output, and updating the next_* and avail_* values accordingly. |
638 | The application can consume the uncompressed output when it wants, for |
639 | example when the output buffer is full (avail_out == 0), or after each |
640 | call of inflate(). If inflate returns Z_OK and with zero avail_out, it |
641 | must be called again after making room in the output buffer because there |
642 | might be more output pending. |
643 | |
644 | If the parameter flush is set to Z_SYNC_FLUSH or Z_PACKET_FLUSH, |
645 | inflate flushes as much output as possible to the output buffer. The |
646 | flushing behavior of inflate is not specified for values of the flush |
647 | parameter other than Z_SYNC_FLUSH, Z_PACKET_FLUSH or Z_FINISH, but the |
648 | current implementation actually flushes as much output as possible |
649 | anyway. For Z_PACKET_FLUSH, inflate checks that once all the input data |
650 | has been consumed, it is expecting to see the length field of a stored |
651 | block; if not, it returns Z_DATA_ERROR. |
652 | |
653 | inflate() should normally be called until it returns Z_STREAM_END or an |
654 | error. However if all decompression is to be performed in a single step |
655 | (a single call of inflate), the parameter flush should be set to |
656 | Z_FINISH. In this case all pending input is processed and all pending |
657 | output is flushed; avail_out must be large enough to hold all the |
658 | uncompressed data. (The size of the uncompressed data may have been saved |
659 | by the compressor for this purpose.) The next operation on this stream must |
660 | be inflateEnd to deallocate the decompression state. The use of Z_FINISH |
661 | is never required, but can be used to inform inflate that a faster routine |
662 | may be used for the single inflate() call. |
663 | |
664 | If a preset dictionary is needed at this point (see inflateSetDictionary |
665 | below), inflate sets strm-adler to the adler32 checksum of the |
666 | dictionary chosen by the compressor and returns Z_NEED_DICT; otherwise |
667 | it sets strm->adler to the adler32 checksum of all output produced |
668 | so far (that is, total_out bytes) and returns Z_OK, Z_STREAM_END or |
669 | an error code as described below. At the end of the stream, inflate() |
670 | checks that its computed adler32 checksum is equal to that saved by the |
671 | compressor and returns Z_STREAM_END only if the checksum is correct. |
672 | |
673 | inflate() returns Z_OK if some progress has been made (more input processed |
674 | or more output produced), Z_STREAM_END if the end of the compressed data has |
675 | been reached and all uncompressed output has been produced, Z_NEED_DICT if a |
676 | preset dictionary is needed at this point, Z_DATA_ERROR if the input data was |
677 | corrupted (input stream not conforming to the zlib format or incorrect |
678 | adler32 checksum), Z_STREAM_ERROR if the stream structure was inconsistent |
679 | (for example if next_in or next_out was NULL), Z_MEM_ERROR if there was not |
680 | enough memory, Z_BUF_ERROR if no progress is possible or if there was not |
681 | enough room in the output buffer when Z_FINISH is used. In the Z_DATA_ERROR |
682 | case, the application may then call inflateSync to look for a good |
683 | compression block. |
684 | */ |
685 | |
686 | |
687 | ZEXTERN int ZEXPORT inflateEnd(z_streamp); |
688 | /* |
689 | All dynamically allocated data structures for this stream are freed. |
690 | This function discards any unprocessed input and does not flush any |
691 | pending output. |
692 | |
693 | inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state |
694 | was inconsistent. In the error case, msg may be set but then points to a |
695 | static string (which must not be deallocated). |
696 | */ |
697 | |
698 | /* Advanced functions */ |
699 | |
700 | /* |
701 | The following functions are needed only in some special applications. |
702 | */ |
703 | |
704 | /* |
705 | ZEXTERN int ZEXPORT deflateInit2(z_streamp, int, int, int, int, int); |
706 | |
707 | This is another version of deflateInit with more compression options. The |
708 | fields next_in, zalloc, zfree and opaque must be initialized before by |
709 | the caller. |
710 | |
711 | The method parameter is the compression method. It must be Z_DEFLATED in |
712 | this version of the library. |
713 | |
714 | The windowBits parameter is the base two logarithm of the window size |
715 | (the size of the history buffer). It should be in the range 8..15 for this |
716 | version of the library. Larger values of this parameter result in better |
717 | compression at the expense of memory usage. The default value is 15 if |
718 | deflateInit is used instead. |
719 | |
720 | The memLevel parameter specifies how much memory should be allocated |
721 | for the internal compression state. memLevel=1 uses minimum memory but |
722 | is slow and reduces compression ratio; memLevel=9 uses maximum memory |
723 | for optimal speed. The default value is 8. See zconf.h for total memory |
724 | usage as a function of windowBits and memLevel. |
725 | |
726 | The strategy parameter is used to tune the compression algorithm. Use the |
727 | value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a |
728 | filter (or predictor), or Z_HUFFMAN_ONLY to force Huffman encoding only (no |
729 | string match). Filtered data consists mostly of small values with a |
730 | somewhat random distribution. In this case, the compression algorithm is |
731 | tuned to compress them better. The effect of Z_FILTERED is to force more |
732 | Huffman coding and less string matching; it is somewhat intermediate |
733 | between Z_DEFAULT and Z_HUFFMAN_ONLY. The strategy parameter only affects |
734 | the compression ratio but not the correctness of the compressed output even |
735 | if it is not set appropriately. |
736 | |
737 | deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough |
738 | memory, Z_STREAM_ERROR if a parameter is invalid (such as an invalid |
739 | method). msg is set to null if there is no error message. deflateInit2 does |
740 | not perform any compression: this will be done by deflate(). |
741 | */ |
742 | |
743 | ZEXTERN int ZEXPORT deflateSetDictionary(z_streamp, const Bytef *, uInt); |
744 | /* |
745 | Initializes the compression dictionary from the given byte sequence |
746 | without producing any compressed output. This function must be called |
747 | immediately after deflateInit, deflateInit2 or deflateReset, before any |
748 | call of deflate. The compressor and decompressor must use exactly the same |
749 | dictionary (see inflateSetDictionary). |
750 | |
751 | The dictionary should consist of strings (byte sequences) that are likely |
752 | to be encountered later in the data to be compressed, with the most commonly |
753 | used strings preferably put towards the end of the dictionary. Using a |
754 | dictionary is most useful when the data to be compressed is short and can be |
755 | predicted with good accuracy; the data can then be compressed better than |
756 | with the default empty dictionary. |
757 | |
758 | Depending on the size of the compression data structures selected by |
759 | deflateInit or deflateInit2, a part of the dictionary may in effect be |
760 | discarded, for example if the dictionary is larger than the window size in |
761 | deflate or deflate2. Thus the strings most likely to be useful should be |
762 | put at the end of the dictionary, not at the front. |
763 | |
764 | Upon return of this function, strm->adler is set to the Adler32 value |
765 | of the dictionary; the decompressor may later use this value to determine |
766 | which dictionary has been used by the compressor. (The Adler32 value |
767 | applies to the whole dictionary even if only a subset of the dictionary is |
768 | actually used by the compressor.) |
769 | |
770 | deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a |
771 | parameter is invalid (such as NULL dictionary) or the stream state is |
772 | inconsistent (for example if deflate has already been called for this stream |
773 | or if the compression method is bsort). deflateSetDictionary does not |
774 | perform any compression: this will be done by deflate(). |
775 | */ |
776 | |
777 | ZEXTERN int ZEXPORT deflateCopy(z_streamp, z_streamp); |
778 | /* |
779 | Sets the destination stream as a complete copy of the source stream. |
780 | |
781 | This function can be useful when several compression strategies will be |
782 | tried, for example when there are several ways of pre-processing the input |
783 | data with a filter. The streams that will be discarded should then be freed |
784 | by calling deflateEnd. Note that deflateCopy duplicates the internal |
785 | compression state which can be quite large, so this strategy is slow and |
786 | can consume lots of memory. |
787 | |
788 | deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not |
789 | enough memory, Z_STREAM_ERROR if the source stream state was inconsistent |
790 | (such as zalloc being NULL). msg is left unchanged in both source and |
791 | destination. |
792 | */ |
793 | |
794 | extern int inflateIncomp(z_stream *); |
795 | /* |
796 | This function adds the data at next_in (avail_in bytes) to the output |
797 | history without performing any output. There must be no pending output, |
798 | and the decompressor must be expecting to see the start of a block. |
799 | Calling this function is equivalent to decompressing a stored block |
800 | containing the data at next_in (except that the data is not output). |
801 | */ |
802 | |
803 | ZEXTERN int ZEXPORT deflateReset(z_streamp); |
804 | /* |
805 | This function is equivalent to deflateEnd followed by deflateInit, |
806 | but does not free and reallocate all the internal compression state. |
807 | The stream will keep the same compression level and any other attributes |
808 | that may have been set by deflateInit2. |
809 | |
810 | deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source |
811 | stream state was inconsistent (such as zalloc or state being NULL). |
812 | */ |
813 | |
814 | ZEXTERN int ZEXPORT deflateParams(z_streamp, int, int); |
815 | /* |
816 | Dynamically update the compression level and compression strategy. The |
817 | interpretation of level and strategy is as in deflateInit2. This can be |
818 | used to switch between compression and straight copy of the input data, or |
819 | to switch to a different kind of input data requiring a different |
820 | strategy. If the compression level is changed, the input available so far |
821 | is compressed with the old level (and may be flushed); the new level will |
822 | take effect only at the next call of deflate(). |
823 | |
824 | Before the call of deflateParams, the stream state must be set as for |
825 | a call of deflate(), since the currently available input may have to |
826 | be compressed and flushed. In particular, strm->avail_out must be non-zero. |
827 | |
828 | deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source |
829 | stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR |
830 | if strm->avail_out was zero. |
831 | */ |
832 | |
833 | ZEXTERN int ZEXPORT deflateOutputPending(z_streamp); |
834 | /* |
835 | Returns the number of bytes of output which are immediately |
836 | available from the compressor (i.e. without any further input |
837 | or flush). |
838 | */ |
839 | |
840 | /* |
841 | ZEXTERN int ZEXPORT inflateInit2(z_streamp, int); |
842 | |
843 | This is another version of inflateInit with an extra parameter. The |
844 | fields next_in, avail_in, zalloc, zfree and opaque must be initialized |
845 | before by the caller. |
846 | |
847 | The windowBits parameter is the base two logarithm of the maximum window |
848 | size (the size of the history buffer). It should be in the range 8..15 for |
849 | this version of the library. The default value is 15 if inflateInit is used |
850 | instead. If a compressed stream with a larger window size is given as |
851 | input, inflate() will return with the error code Z_DATA_ERROR instead of |
852 | trying to allocate a larger window. |
853 | |
854 | inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough |
855 | memory, Z_STREAM_ERROR if a parameter is invalid (such as a negative |
856 | memLevel). msg is set to null if there is no error message. inflateInit2 |
857 | does not perform any decompression apart from reading the zlib header if |
858 | present: this will be done by inflate(). (So next_in and avail_in may be |
859 | modified, but next_out and avail_out are unchanged.) |
860 | */ |
861 | |
862 | ZEXTERN int ZEXPORT inflateSetDictionary(z_streamp, const Bytef *, uInt); |
863 | /* |
864 | Initializes the decompression dictionary from the given uncompressed byte |
865 | sequence. This function must be called immediately after a call of inflate |
866 | if this call returned Z_NEED_DICT. The dictionary chosen by the compressor |
867 | can be determined from the Adler32 value returned by this call of |
868 | inflate. The compressor and decompressor must use exactly the same |
869 | dictionary (see deflateSetDictionary). |
870 | |
871 | inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a |
872 | parameter is invalid (such as NULL dictionary) or the stream state is |
873 | inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the |
874 | expected one (incorrect Adler32 value). inflateSetDictionary does not |
875 | perform any decompression: this will be done by subsequent calls of |
876 | inflate(). |
877 | */ |
878 | |
879 | ZEXTERN int ZEXPORT inflateSync(z_streamp); |
880 | /* |
881 | Skips invalid compressed data until a full flush point (see above the |
882 | description of deflate with Z_FULL_FLUSH) can be found, or until all |
883 | available input is skipped. No output is provided. |
884 | |
885 | inflateSync returns Z_OK if a full flush point has been found, Z_BUF_ERROR |
886 | if no more input was provided, Z_DATA_ERROR if no flush point has been found, |
887 | or Z_STREAM_ERROR if the stream structure was inconsistent. In the success |
888 | case, the application may save the current current value of total_in which |
889 | indicates where valid compressed data was found. In the error case, the |
890 | application may repeatedly call inflateSync, providing more input each time, |
891 | until success or end of the input data. |
892 | */ |
893 | |
894 | ZEXTERN int ZEXPORT inflateReset(z_streamp); |
895 | /* |
896 | This function is equivalent to inflateEnd followed by inflateInit, |
897 | but does not free and reallocate all the internal decompression state. |
898 | The stream will keep attributes that may have been set by inflateInit2. |
899 | |
900 | inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source |
901 | stream state was inconsistent (such as zalloc or state being NULL). |
902 | */ |
903 | |
904 | |
905 | /* utility functions */ |
906 | |
907 | /* |
908 | The following utility functions are implemented on top of the |
909 | basic stream-oriented functions. To simplify the interface, some |
910 | default options are assumed (compression level and memory usage, |
911 | standard memory allocation functions). The source code of these |
912 | utility functions can easily be modified if you need special options. |
913 | */ |
914 | |
915 | ZEXTERN int ZEXPORT compress(Bytef *, uLongf *, const Bytef *, uLong); |
916 | /* |
917 | Compresses the source buffer into the destination buffer. sourceLen is |
918 | the byte length of the source buffer. Upon entry, destLen is the total |
919 | size of the destination buffer, which must be at least 0.1% larger than |
920 | sourceLen plus 12 bytes. Upon exit, destLen is the actual size of the |
921 | compressed buffer. |
922 | This function can be used to compress a whole file at once if the |
923 | input file is mmap'ed. |
924 | compress returns Z_OK if success, Z_MEM_ERROR if there was not |
925 | enough memory, Z_BUF_ERROR if there was not enough room in the output |
926 | buffer. |
927 | */ |
928 | |
929 | ZEXTERN int ZEXPORT compress2(Bytef *, uLongf *, const Bytef *, |
930 | uLong, int); |
931 | /* |
932 | Compresses the source buffer into the destination buffer. The level |
933 | parameter has the same meaning as in deflateInit. sourceLen is the byte |
934 | length of the source buffer. Upon entry, destLen is the total size of the |
935 | destination buffer, which must be at least 0.1% larger than sourceLen plus |
936 | 12 bytes. Upon exit, destLen is the actual size of the compressed buffer. |
937 | |
938 | compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough |
939 | memory, Z_BUF_ERROR if there was not enough room in the output buffer, |
940 | Z_STREAM_ERROR if the level parameter is invalid. |
941 | */ |
942 | |
943 | ZEXTERN int ZEXPORT uncompress(Bytef *, uLongf *, const Bytef *, uLong); |
944 | /* |
945 | Decompresses the source buffer into the destination buffer. sourceLen is |
946 | the byte length of the source buffer. Upon entry, destLen is the total |
947 | size of the destination buffer, which must be large enough to hold the |
948 | entire uncompressed data. (The size of the uncompressed data must have |
949 | been saved previously by the compressor and transmitted to the decompressor |
950 | by some mechanism outside the scope of this compression library.) |
951 | Upon exit, destLen is the actual size of the compressed buffer. |
952 | This function can be used to decompress a whole file at once if the |
953 | input file is mmap'ed. |
954 | |
955 | uncompress returns Z_OK if success, Z_MEM_ERROR if there was not |
956 | enough memory, Z_BUF_ERROR if there was not enough room in the output |
957 | buffer, or Z_DATA_ERROR if the input data was corrupted. |
958 | */ |
959 | |
960 | |
961 | typedef voidp gzFile; |
962 | |
963 | ZEXTERN gzFile ZEXPORT gzopen(const char *, const char *); |
964 | /* |
965 | Opens a gzip (.gz) file for reading or writing. The mode parameter |
966 | is as in fopen ("rb" or "wb") but can also include a compression level |
967 | ("wb9") or a strategy: 'f' for filtered data as in "wb6f", 'h' for |
968 | Huffman only compression as in "wb1h". (See the description |
969 | of deflateInit2 for more information about the strategy parameter.) |
970 | |
971 | gzopen can be used to read a file which is not in gzip format; in this |
972 | case gzread will directly read from the file without decompression. |
973 | |
974 | gzopen returns NULL if the file could not be opened or if there was |
975 | insufficient memory to allocate the (de)compression state; errno |
976 | can be checked to distinguish the two cases (if errno is zero, the |
977 | zlib error is Z_MEM_ERROR). */ |
978 | |
979 | ZEXTERN gzFile ZEXPORT gzdopen(int, const char *); |
980 | /* |
981 | gzdopen() associates a gzFile with the file descriptor fd. File |
982 | descriptors are obtained from calls like open, dup, creat, pipe or |
983 | fileno (in the file has been previously opened with fopen). |
984 | The mode parameter is as in gzopen. |
985 | The next call of gzclose on the returned gzFile will also close the |
986 | file descriptor fd, just like fclose(fdopen(fd), mode) closes the file |
987 | descriptor fd. If you want to keep fd open, use gzdopen(dup(fd), mode). |
988 | gzdopen returns NULL if there was insufficient memory to allocate |
989 | the (de)compression state. |
990 | */ |
991 | |
992 | ZEXTERN int ZEXPORT gzsetparams(gzFile, int, int); |
993 | /* |
994 | Dynamically update the compression level or strategy. See the description |
995 | of deflateInit2 for the meaning of these parameters. |
996 | gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not |
997 | opened for writing. |
998 | */ |
999 | |
1000 | ZEXTERN int ZEXPORT gzread(gzFile, voidp, unsigned); |
1001 | /* |
1002 | Reads the given number of uncompressed bytes from the compressed file. |
1003 | If the input file was not in gzip format, gzread copies the given number |
1004 | of bytes into the buffer. |
1005 | gzread returns the number of uncompressed bytes actually read (0 for |
1006 | end of file, -1 for error). */ |
1007 | |
1008 | ZEXTERN int ZEXPORT gzwrite(gzFile, const voidp, unsigned); |
1009 | /* |
1010 | Writes the given number of uncompressed bytes into the compressed file. |
1011 | gzwrite returns the number of uncompressed bytes actually written |
1012 | (0 in case of error). |
1013 | */ |
1014 | |
1015 | ZEXTERN int ZEXPORTVA gzprintf(gzFile, const char *, ...) |
1016 | __attribute__((__format__(__printf__, 2, 3))); |
1017 | /* |
1018 | Converts, formats, and writes the args to the compressed file under |
1019 | control of the format string, as in fprintf. gzprintf returns the number of |
1020 | uncompressed bytes actually written (0 in case of error). |
1021 | */ |
1022 | |
1023 | ZEXTERN int ZEXPORT gzputs(gzFile, const char *); |
1024 | /* |
1025 | Writes the given null-terminated string to the compressed file, excluding |
1026 | the terminating null character. |
1027 | gzputs returns the number of characters written, or -1 in case of error. |
1028 | */ |
1029 | |
1030 | ZEXTERN char * ZEXPORT gzgets(gzFile, char *, int); |
1031 | /* |
1032 | Reads bytes from the compressed file until len-1 characters are read, or |
1033 | a newline character is read and transferred to buf, or an end-of-file |
1034 | condition is encountered. The string is then terminated with a null |
1035 | character. |
1036 | gzgets returns buf, or Z_NULL in case of error. |
1037 | */ |
1038 | |
1039 | ZEXTERN int ZEXPORT gzputc(gzFile, int); |
1040 | /* |
1041 | Writes c, converted to an unsigned char, into the compressed file. |
1042 | gzputc returns the value that was written, or -1 in case of error. |
1043 | */ |
1044 | |
1045 | ZEXTERN int ZEXPORT gzgetc(gzFile); |
1046 | /* |
1047 | Reads one byte from the compressed file. gzgetc returns this byte |
1048 | or -1 in case of end of file or error. |
1049 | */ |
1050 | |
1051 | ZEXTERN int ZEXPORT gzflush(gzFile, int); |
1052 | /* |
1053 | Flushes all pending output into the compressed file. The parameter |
1054 | flush is as in the deflate() function. The return value is the zlib |
1055 | error number (see function gzerror below). gzflush returns Z_OK if |
1056 | the flush parameter is Z_FINISH and all output could be flushed. |
1057 | gzflush should be called only when strictly necessary because it can |
1058 | degrade compression. |
1059 | |
1060 | */ |
1061 | |
1062 | /* |
1063 | * NetBSD note: |
1064 | * "long" gzseek has been there till Oct 1999 (1.4L), which was wrong. |
1065 | */ |
1066 | ZEXTERN z_off_t ZEXPORT gzseek(gzFile, z_off_t, int); |
1067 | /* |
1068 | Sets the starting position for the next gzread or gzwrite on the |
1069 | given compressed file. The offset represents a number of bytes in the |
1070 | uncompressed data stream. The whence parameter is defined as in lseek(2); |
1071 | the value SEEK_END is not supported. |
1072 | If the file is opened for reading, this function is emulated but can be |
1073 | extremely slow. If the file is opened for writing, only forward seeks are |
1074 | supported; gzseek then compresses a sequence of zeroes up to the new |
1075 | starting position. |
1076 | |
1077 | gzseek returns the resulting offset location as measured in bytes from |
1078 | the beginning of the uncompressed stream, or -1 in case of error, in |
1079 | particular if the file is opened for writing and the new starting position |
1080 | would be before the current position. |
1081 | */ |
1082 | |
1083 | ZEXTERN int ZEXPORT gzrewind(gzFile); |
1084 | /* |
1085 | Rewinds the given file. This function is supported only for reading. |
1086 | |
1087 | gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET) |
1088 | */ |
1089 | |
1090 | /* |
1091 | * NetBSD note: |
1092 | * "long" gztell has been there till Oct 1999 (1.4L), which was wrong. |
1093 | */ |
1094 | ZEXTERN z_off_t ZEXPORT gztell(gzFile); |
1095 | /* |
1096 | Returns the starting position for the next gzread or gzwrite on the |
1097 | given compressed file. This position represents a number of bytes in the |
1098 | uncompressed data stream. |
1099 | |
1100 | gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR) |
1101 | */ |
1102 | |
1103 | ZEXTERN int ZEXPORT gzeof(gzFile); |
1104 | /* |
1105 | Returns 1 when EOF has previously been detected reading the given |
1106 | input stream, otherwise zero. |
1107 | */ |
1108 | |
1109 | ZEXTERN int ZEXPORT gzclose(gzFile); |
1110 | /* |
1111 | Flushes all pending output if necessary, closes the compressed file |
1112 | and deallocates all the (de)compression state. The return value is the zlib |
1113 | error number (see function gzerror below). |
1114 | */ |
1115 | |
1116 | ZEXTERN const char * ZEXPORT gzerror(gzFile, int *); |
1117 | /* |
1118 | Returns the error message for the last error which occurred on the |
1119 | given compressed file. errnum is set to zlib error number. If an |
1120 | error occurred in the file system and not in the compression library, |
1121 | errnum is set to Z_ERRNO and the application may consult errno |
1122 | to get the exact error code. |
1123 | */ |
1124 | |
1125 | /* checksum functions */ |
1126 | |
1127 | /* |
1128 | These functions are not related to compression but are exported |
1129 | anyway because they might be useful in applications using the |
1130 | compression library. |
1131 | */ |
1132 | |
1133 | ZEXTERN uLong ZEXPORT adler32(uLong, const Bytef *, uInt); |
1134 | |
1135 | /* |
1136 | Update a running Adler-32 checksum with the bytes buf[0..len-1] and |
1137 | return the updated checksum. If buf is NULL, this function returns |
1138 | the required initial value for the checksum. |
1139 | An Adler-32 checksum is almost as reliable as a CRC32 but can be computed |
1140 | much faster. Usage example: |
1141 | |
1142 | uLong adler = adler32(0L, Z_NULL, 0); |
1143 | |
1144 | while (read_buffer(buffer, length) != EOF) { |
1145 | adler = adler32(adler, buffer, length); |
1146 | } |
1147 | if (adler != original_adler) error(); |
1148 | */ |
1149 | |
1150 | #ifdef STANDALONE |
1151 | ZEXTERN uLong ZEXPORT crc32(uLong, const Bytef *, uInt); |
1152 | #endif |
1153 | /* |
1154 | Update a running crc with the bytes buf[0..len-1] and return the updated |
1155 | crc. If buf is NULL, this function returns the required initial value |
1156 | for the crc. Pre- and post-conditioning (one's complement) is performed |
1157 | within this function so it shouldn't be done by the application. |
1158 | Usage example: |
1159 | |
1160 | uLong crc = crc32(0L, Z_NULL, 0); |
1161 | |
1162 | while (read_buffer(buffer, length) != EOF) { |
1163 | crc = crc32(crc, buffer, length); |
1164 | } |
1165 | if (crc != original_crc) error(); |
1166 | */ |
1167 | |
1168 | |
1169 | /* various hacks, don't look :) */ |
1170 | |
1171 | /* deflateInit and inflateInit are macros to allow checking the zlib version |
1172 | * and the compiler's view of z_stream: |
1173 | */ |
1174 | ZEXTERN int ZEXPORT deflateInit_(z_streamp, int, const char *, int); |
1175 | ZEXTERN int ZEXPORT inflateInit_(z_streamp, const char *, int); |
1176 | ZEXTERN int ZEXPORT deflateInit2_(z_streamp, int, int, int, int, |
1177 | int, const char *, int); |
1178 | ZEXTERN int ZEXPORT inflateInit2_(z_streamp, int, const char *, int); |
1179 | #define deflateInit(strm, level) \ |
1180 | deflateInit_((strm), (level), ZLIB_VERSION, sizeof(z_stream)) |
1181 | #define inflateInit(strm) \ |
1182 | inflateInit_((strm), ZLIB_VERSION, sizeof(z_stream)) |
1183 | #define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \ |
1184 | deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\ |
1185 | (strategy), ZLIB_VERSION, sizeof(z_stream)) |
1186 | #define inflateInit2(strm, windowBits) \ |
1187 | inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream)) |
1188 | |
1189 | |
1190 | #if !defined(Z_UTIL_H) && !defined(NO_DUMMY_DECL) |
1191 | struct internal_state {int dummy;}; /* hack for buggy compilers */ |
1192 | #endif |
1193 | |
1194 | ZEXTERN const char * ZEXPORT zError(int); |
1195 | ZEXTERN int ZEXPORT inflateSyncPoint(z_streamp); |
1196 | ZEXTERN const uLongf * ZEXPORT get_crc_table(void); |
1197 | |
1198 | #ifdef __cplusplus |
1199 | } |
1200 | #endif |
1201 | #endif /* !ZLIB_H */ |
1202 | |
1203 | #endif /* !_NET_ZLIB_H_ */ |
1204 | /* -- zlib.h */ |
1205 | |